4,5-Dichloro-imidazole-1-carboxylic acid aryl esters and their use as plant protection agents

ABSTRACT

A 4,5-dichloro-imidazole-1-carboxylic acid aryl ester of the formula ##STR1## in which X represents trifluoromethyl, cyano or a group ##STR2## in which R 1  represents an optionally substituted saturated or unsaturated aliphatic radical, R 2  represents hydrogen, alkyl with 1 to 8 carbon atoms, alkenyl with up to 8 carbon atoms or the formyl group, R 3  represents alkyl with 1 to 8 carbon atoms or alkenyl or alkynyl each with up to 8 carbon atoms, it being possible for each of these alkyl, alkenyl and alkynyl radicals to carry one or more substituents, or represents cycloalkyl with 5 to 7 carbon atoms in the ring which is optionally substituted by alkyl with 1 to 6 carbon atoms, or represents phenyl which may optionally carry one or more substituents, or R 2  and R 3  conjointly with the adjoining nitrogen atom form an optionally substituted 5- to 7-membered heterocyclic radical in which 1 to 3 ring members may be selected from oxygen, sulfur and nitrogen, Y represents halogen, alkyl with 1 to 6 carbon atoms, trifluoromethyl, alkoxy with 1 to 6 carbon atoms, nitro, cyano or a ##STR3## group, in which R 4  represents alkyl with 1 to 6 carbon atoms and n represents 0, 1, 2, 3, 4, or 5, which possesses plant protection properties especially herbicidal and plant growth regulant properties.

The present invention relates to certain new4,5-dichloro-imidazole-1-carboxylic acid aryl esters which possess plantprotection properties, e.g., herbicidal, insecticidal or miticidalproperties, as well as plant growth regulating and acarid killingproperties, to a process for their preparation, to active compositionsin the form of mixtures of such compounds with solid, liquid and gaseousdiluents especially of the type that forms dispersions, emulsions orsuspensions and to the use of such new4,5-dichloro-imidazole-1-carboxylic acid aryl esters as plant protectionagents.

It has been disclosed in Nature 215, 275 (1967) that certain2-trifluoromethyl-banzimidazole-1-carboxylic acid aryl esters possessacaricidal properties. For example5,6-dichloro-2-trifluoromethyl-benzimidazole-1-carboxylic acid phenylester can be used for combating mites. However, because of variousshortcomings this compound has not attained any importance in practice.

Furthermore it has been disclosed in Netherlands Patent Application7,004,376 that certain benzimidazole-2-carboxylic acid derivativesexhibit herbicidal properties. Thus, benzimiazole-2-carboxylic acidnitrile can be used for combating weeds. However, the activity of thiscompound is not always satisfactory, especially when low amounts areused.

The present invention now provides, as new compounds, the4,5-dichloro-imidazole-1-carboxylic acid aryl esters of the generalformula ##STR4## in which

X represents, trifluoromethyl, cyano or a group ##STR5## in which

R¹ represents a saturated or unsaturated aliphatic radical, which can becarrying one or more substituents selected from halogen, alkoxy with 1to 6 carbon atoms and alkylmercapto with 1 to 6 carbon atoms,

R² represents hydrogen, alkyl with 1 to 8 carbon atoms, alkenyl with upto 8 carbon atoms or the formyl group,

R³ represents alkyl with 1 to 8 carbon atoms or alkenyl or alkynyl eachwith up to 8 carbon atoms, it being possible for each of these alkyl,alkenyl and alkynyl radicals to carry one or more substituents selectedfrom alkoxy with 1 to 4 carbon atoms, alkylmercapto with 1 to 4 carbonatoms, phenyl (which may optionally carry one or more substituentsselected from halogen, alkyl with 1 to 4 carbon atoms, trifluoromethyland alkoxy with 1 to 4 carbon atoms), furyl or thienyl, or representscycloalkyl with 5 to 7 carbon atoms in the ring which is optionallysubstituted by alkyl with 1 to 6 carbon atoms, or represents phenylwhich may optionally carry one or more substituents selected fromhalogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbonatoms, alkylmercapto with 1 to 4 carbon atoms and trifluoromethyl, or

R² and R³ conjointly with the adjoining nitrogen atom form an optionallysubstituted 5-membered to 7-membered heterocyclic ring in which 1 to 3ring members may be selected from oxygen, sulphur and nitrogen,

Y represents halogen, alkyl with 1 to 6 carbon atoms, trifluoromethyl,alkoxy with 1 to 6 carbon atoms, alkylmercapto with 1 to 6 carbons,nitro, cyano or the ##STR6## group, in which

R⁴ represents alkyl with 1 to 6 carbon atoms, and

n represents 0, 1, 2, 3, 4 or 5.

Surprisingly, the 4,5-dichloro-imidazole-1-carboxylic acid aryl estersaccording to the invention of the formula (I), exhibit a substantiallybetter herbicidal activity than benzimidazole-2-carboxylic acid nitrile,known from the state of the art, which is the nearest active compound ofthe same type of action. In addition, the compounds according to theinvention are very suitable for use as plant growth regulators and forcombating insects and acarids, especially mites. Accordingly, thecompounds according to the invention represent a valuable enrichment ofthe art.

Preferably X represents trifluoromethyl, cyano or a group --CO--OR¹ or--CO--NR² R³ in which R¹ represents a saturated or unsaturated aliphaticradical with 1 to 6 carbon atoms, especially straight-chain or branchedalkyl with 1 to 6 carbon atoms or straight-chain or branched alkenyl oralkynyl, each with up to 6 carbon atoms, which aliphatic radical cancarry one or more substituents selected from fluorine, chlorine,bromine, alkoxy with 1 to 4 carbon atoms and alkylmercapto with 1 to 4carbon atoms;

R² represents hydrogen, straight-chain or branched alkyl with 1 to 6carbon atoms, straight-chain or branched alkenyl with up to 6 carbonatoms or the formyl group;

R³ represents straight-chain or branched alkyl with 1 to 6 carbon atomsor straight-chain or branched alkenyl or alkynyl each with up to 6carbon atoms, it being possible for each of these radicals to carry oneor more substituents selected from furyl, thienyl, alkoxy with 1 to 3carbon atoms, alkylmercapto with 1 to 3 carbon atoms and phenyl whichmay itself optionally carry one or more substituents selected fromfluorine, chlorine, bromine, alkyl with 1 to 3 carbon atoms, alkoxy with1 to 3 carbon atoms and trifluoromethyl, or represents a cyclopentyl orcyclohexyl group which is optionally substituted by alkyl with 1 to 4carbon atoms, or represents phenyl which optionally carries one or moresubstituents selected from fluorine, chlorine, bromine, alkyl with 1 to3 carbon atoms, alkoxy with 1 to 3 carbon atoms, alkylmercapto with 1 to3 carbon atoms and trifluoromethyl; or

R² and R³ conjointly with the adjoining nitrogen atom represent asaturated or unsaturated heterocyclic ring with 5 to 7 ring members, itbeing possible for the heterocyclic ring also to contain, additionallyto the said nitrogen atom already mentioned, 1 or 2 further hetero-atomsselected from oxygen, sulphur and nitrogen atoms (heterocyclic radicalswhich may be mentioned as examples being pyrrolidinyl, piperidinyl,piperazinyl, hexamethyleneimidinyl, morpholinyl, thiamorpholinyl,1,2,4-triazinyl and imidazolyl);

Y represents fluorine, chlorine, bromine, alkyl with 1 to 4 carbonatoms, alkoxy with 1 to 4 carbon atoms, alkylmercapto with 1 to 4 carbonatoms, trifluoromethyl, nitro, cyano or a --CO--OR⁴ group, in which R⁴represents alkyl with 1 to 4 carbon atoms; and

n represents 0, 1, 2 or 3.

The present invention also provides a process for the preparation of a4,5-dichloro-imidazole-1-carboxylic acid aryl ester of the formula (I)in which a 4,5-dichloro-imidazole-2-carboxylic acid derivative of thegeneral formula ##STR7## in which

X has the above-mentioned meaning, is reacted, if desired, in thepresence of a diluent, with a chloroformic acid aryl ester of thegeneral formula ##STR8## in which

Y and n have the above-mentioned meanings, the compond (II) beingemployed as such as in the presence of an acid-binding agent or in theform of an alkali metal salt, alkaline earth metal salt or amine salt.

If 4,5-dichloro-imidazole-2-carboxylic acid nitrile and chloroformicacid phenyl ester are used as starting materials, the course of thereaction, in accordance with the process of the invention, can berepresented by the following equation: ##STR9##

The following may be mentioned individually as examples of the4,5-dichloro-imidazole-2-carboxylic acid derivatives of the formula (II)which may be used according to the invention:4,5-dichloro-2-trifluoromethyl-imidazole,4,5-dichloro-2-cyano-imidazole, 4,5-dichloro-imidazole-2-carboxylic acidmethyl ester, 4,5-dichloro-imidazole-2-carboxylic acid ethyl ester,4,5-dichloro-imidazole-2-carboxylic acid isopropyl ester,4,5-dichloro-imidazole-2-carboxylic acid butyl ester,4,5-dichloro-imidazole-2-carboxylic acid sec.-butyl ester,4,5-dichloro-imidazole-2-carboxylic acid tert.-butyl ester,4,5-dichloro-imidazole-2-carboxylic acid neopentyl ester,4,5-dichloro-imidazole-2-carboxylic acid hexyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2-chloro-ethyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2,2,2-trichloroethyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2-methoxy-ethyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2-butoxy-ethyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2-ethylmercapto-ethyl ester,4,5-dichloro-imidazole-2-carboxylic acid allyl ester,4,5-dichloro-imidazole-2-carboxylic acid propargyl ester,4,5-dichloro-imidazole-2-carboxylic acid 2-methyl-but-3-in-2-yl ester,4,5-dichloro-imidazole-2-carboxylic acid methylamide,4,5-dichloro-imidazole-2-carboxylic acid ethylamide, 4,5-dichloro-imidazole-2-carboxylic acid isopropylamide,4,5-dichloro-imidazole-2-carboxylic acid sec.-butylamide,4,5-dichloro-imidazole-2-carboxylic acid tert.-butylamide,4,5-dichloro-imidazole-2-carboxylic acid allylamide,4,5-dichloro-imidazole-2-carboxylic acid 2-methyl-but-3-in-2-yl amide,4,5-dichloro-imidazole-2-carboxylic acid 2-ethoxymethylamide,4,5-dichloro-imidazole-2-carboxylic acid 3-methoxy-propylamide,4,5-dichloro-imidazole-2-carboxylic acid 2-methylmercapto-ethylamide,4,5-dichloro-imidazole-2-carboxylic acid benzylamide,4,5-dichloro-imidazole-2-carboxylic acid 4-chlorobenzylamide,4,5-dichloro-imidazole-2-carboxylic acid 4-methylbenzylamide,4,5-dichloro-imidazole-2-carboxylic acid 4-trifluoromethyl-benzylamide,4,5-dichloro-imidazole-2-carboxylic acid 4-methoxy-benzylamide,4,5-dichloro-imidazole-2-carboxylic acid cyclopentylamide,4,5-dichloro-imidazole-2-carboxylic acid cyclohexylamide,4,5-dichloro-imidazole-2-carboxylic acid anilide,4,5-dichloro-imidazole-2-carboxylic acid 4-chloroanilide,4,5-dichloro-imidazole-2-carboxylic acid 3,4-dichloro-anilide,4,5-dichloro-imidazole-2-carboxylic acid 4-methyl-anilide,4,5-dichloro-imidazole-2-carboxylic acid 4-methoxy-anilide,4,5-dichloro-imidazole-2-carboxylic acid4-chloro-3-trifluoromethyl-anilide, 4,5-dichloro-imidazole-2-carboxylicacid 2-furyl-methylamide, 4,5-dichloro-imidazole-2-carboxylic acid2-thienylmethylamide, 4,5-dichloro-imidazole-2-carboxylic aciddimethylamide, 4,5-dichloro-imidazole-2-carboxylic acid diethylamide,4,5-dichloro-imidazole-2-carboxylic acid diisopropylamide,4,5-dichloro-imidazole-2-carboxylic acid N-methylbutylamide,4,5-dichloro-imidazole-2-carboxylic acid N-methylcyclohexylamide,4,5-dichloro-imidazole-2-carboxylic acid N-methyl-anilide,4,5-dichloro-imidazole-2-carboxylic acid N-formyl-methylamide,4,5-dichloro-imidazole-2-carboxylic acid N-formyl-isopropylamide,4,5-dichloro-imidazole-2-carboxylic acid pyrrolidide,4,5-dichloro-imidazole-2-carboxylic acid piperidide,4,5-dichloro-imidazole-2-carboxylic acid hexamethyleneimide,4,5-dichloro-imidazole-2-carboxylic acid morpholide and4,5-dichloro-imidazole-2-carboxylic acid thiamorpholide.

The 4,5-dichloro-imidazole-2-carboxylic acid derivatives of the formula(II) required as starting compounds have not previously been describedin the literature. However, they can be prepared in a simple mannerstarting from 4,5-dichloro-2-dichloromethylene-imidazole of the formula(IV) 4,5-dichloro-2-trichloromethyl-imidazole of the formula (V) or thecompound of the formula (VI) ##STR10## Thus, for example,4,5-dichloro-2-trifluoromethyl-imidazole is obtained by reacting4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) or4,5-dichloro-2-trichloromethyl-imidazole of the formula (V) with excesshydrogen fluoride, if desired in the present of an inert diluent, attemperatures between 0° C. and 200° C., preferably between 20° C. and150° C. The reaction product is isolated by stripping off the excesshydrogen fluoride after completion of the reaction, dissolving theresidue in tetrahydrofuran, adding sodium fluoride and then filteringand distilling the mixture.

Expressed in terms of formulas, the course of this reaction can beillustrated as follows: ##STR11##

4,5-Dichloro-2-cyano-imidazole can be prepared by reacting4,5-dichloro-2-trichloromethyl-imidazole of the formula (V) with excessammonia, if appropriate in the presence of a diluent, such as, forexample, dioxan, tetrahydrofuran or ethanol, at temperatures between-20° C. and +50° C. Working up is effected by filtering off theinsoluble constituents after completion of the reaction, evaporating thefiltrate, dissolving the combined residues in hot water andprecipitating the product by acidifying with dilute mineral acid.

Expressed in terms of formulas, the course of this reaction can beillustrated as follows: ##STR12##

Those compounds of the formula (II), in which X represents the ##STR13##group, can be prepared by reacting4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) or4,5-dichloro-2-trichloro-methyl-imidazole of the formula (V) withalcohols of the formula

    R.sup.1 --OH                                               (VII)

in which

R¹ has the meaning stated above, if desired in the presence of anacid-binding agent, for example an alkali metal hydroxide or carbonateor alkaline earth metal hydroxide or carbonate or a tertiary amine, and,if desired, in the presence of an inert diluent, for example benzine(gasolene), carbon tetrachloride, toluene, chlorobenzene, diethyl ether,tetrahydrofuran or dioxane, at temperatures between 0° C. and 150° C.The reaction products are in general isolated by distilling off thevolatile constituents after completion of the reaction, and, if desired,purifying the product which thus remains, by recrystallization.

Expressed in terms of formulas, the course of this reaction can beillustrated as follows: ##STR14##

Those compounds of the formula (II), in which X represents a ##STR15##group, can be prepared by reacting4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) with, permole, at least 2 moles of a formic amide of the formula ##STR16## inwhich

R³ has the meaning stated above, if desired in the presence of adiluent, such as, for example, an aliphatic or aromatic hydrocarbon, anopen-chain or cyclic ether or an aliphatic nitrile, at temperaturesbetween -10° C. and +110° C. The working up is effected by pouring thereaction mixture, after completion of the reaction, into ice water.Hereupon, the product precipitates in a crystalline form.

Expressed in terms of formulas, the course of this reaction can beillustrated as follows: ##STR17##

If, in the reaction described above, at least 1 mole of water isfurthermore added per mole of 4,5-dichloro-2-dichloromethylene-imidazoleof the formula (IV), a compound of the formula (II), in which R²represents hydrogen, is obtained directly, at a reaction temperature ofbetween 50° C. and 150° C., in a one-vessel process.

Expressed in terms of formulas, the course of this reaction can beillustrated as follows: ##STR18##

Those compounds of the formula (II), in which X represents a ##STR19##group, may be prepared by (a) reacting4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) or4,5-dichloro-2-trichloromethyl-imidazole of the formula (V), in a firststage, with an amine hydrochloride of the formula ##STR20## in which

R² and R² have the meanings stated above, in the presence of an aproticsolvent, such as a cyclic ether, for example tetrahydrofuran or dioxan,at temperatures between 50° C. and 200° C., and then, in a second stage,treating the resulting intermediate product, without prior isolation,with water at temperatures between 0° C. and 100° C., or by

(b) reacting the compound of the formula (VI) with an amine of theformula ##STR21## in which

R² and R³ have the meanings stated above, if appropriate in the presenceof a diluent, such as, for example, water, alcohol, ether, ketone,aliphatic or aromatic hydrocarbons, dimethylformamide ordimethylsulphoxide, at temperatures between -20° C. and +120° C.

Both in the process according to variant (a) and in the processaccording to variant (b), working up takes place by pouring the reactionmixture, after completion of the reaction, into water, if necessarywhilst cooling. Hereupon, the product is obtained in a solid form.

Expressed in terms of formulas, the course of the reactions according toprocess variants (a) and (b) can be illustrated as follows: ##STR22##

The 4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) isalready known and described in German Offenlegungsschrift 2,454,326.

The 4,5-dichloro-2-trichloromethyl-imidazole of the formula (V) has notpreviously been described in the literature. However, it can be preparedin a simple manner by treating4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV) with dryhydrogen chloride at temperatures between -20° C. and +100° C., ifappropriate in the presence of a diluent. Suitable diluents for this areall inert organic solvents, especially aliphatic or aromatichydrocarbons or halogeno-hydrocarbons, such as, for example, benzine,benzene, toluene, methylene chloride, chloroform, carbon tetrachlorideor chlorobenzene, and ethers such as, for example, diethyl ether,dibutyl ether, tetrahydrofuran and dioxan.

The compound of the formula ##STR23## has not previously been describedin the literature. However, it can be prepared in a simple manner bytreating 4,5-dichloro-2-dichloromethylene-imidazole of the formula (IV)with water at temperatures between 0° C. and 100° C.

The compounds of the formulas (VII), (IX), (XII) and also (XIII)required as starting materials in preparing the compounds of the formula(II) are known or can be prepared in accordance with processes whichhave already been described.

The compounds of the formula (III) are largely known. Those chloroformicacid aryl esters which have not previously been described can beprepared in accordance with known processes by reacting thecorresponding phenols with phosgene.

The following may be mentioned individually as examples of chloroformicacid aryl esters of the formula (III): chloroformic acid phenyl ester,chloroformic acid 2-chlorophenyl ester, chloroformic acid2,4-dichlorophenyl ester, chloroformic acid pentachlorophenyl ester,chloroformic acid 4-bromophenyl ester, chloroformic acid 4-bopophenylester, chloroformic acid 4-methylphenyl ester, chloroformic acid2-methyl-4-chlorophenyl ester, chloroformic acid 4-isopropylphenylester, chloroformic acid 2-isopropoxyphenyl ester, chloroformic acid4-methoxyphenyl ester, chloroformic acid 4-methylmercaptophenyl ester,chloroformic acid 4-nitrophenyl ester, chloroformic acid3-trifluoromethylphenyl ester, chloroformic acid 4-cyanophenyl ester andchloroformic acid 4-carbethoxyphenyl ester.

All inert organic solvents can be used as diluents in carrying out theprocess according to the invention, especially aliphatic and aromatichydrocarbons and halogenohydrocarbons, such as benzine (gasoline),benzene, toluene, methylene chloride, chloroform, carbon tetrachlorideand chlorobenzene; ethers such as diethyl ether, tetrahydrofuran anddioxan; ketones such as acetone and methyl isopropyl ketone; carboxylicacid esters and nitriles, such as ethyl acetate and acetonitrile; andstrongly polar solvents such as, for example, dimethylformamide. Attimes, water or a mixture of water and an organic solvent can also beemployed.

All customary acid acceptors can be used as acid-binding agents.Preferred acid acceptors include alkali metal hydroxides, alkaline earthmetal oxides and alkaline earth metal hydroxides, alkali metalcarbonates and alkaline earth metal carbonates and also tertiary aminessuch as triethylamine, N,N-dimethylaniline, N,N-dimethylbenzylamine andpyridine.

In the process according to the invention, the reaction temperaturesused for the reaction can be varied within a substantial range. Ingeneral, the reaction is carried out at from -25° C. to +100° C.,preferably from -5° C. to +80° C.

In carrying out the process according to the invention, 1 mole of achloroformic acid aryl ester of the formula (III) and at least 1equivalent of an acid-binding agent are employed per mole of a4,5-dichloro-imidazole-2-carboxylic acid derivative of the formula (II).However, it is also possible first to convert the4,5-dichloroimidazole-2-carboxylic acid derivative of the formula (II)into an alkali metal salt, alkaline earth metal salt or amine salt inaccordance with customary methods, and then to react the salt concernedwith an equimolar amount of chloroformic acid aryl ester of the formula(III). In these cases, the addition of an acid-binding agent issuperfluous.

The isolation of the reaction product may be carried out in accordancewith customary methods. In general, the procedure followed is that aftercompletion of the reaction the salts formed are filtered off, thefiltrate is evaporated and the residue which thus remains is eitherdistilled or is purified by treatment with water and, if appropriate, isadditionally also recrystallised.

The following may be mentioned individually as examples of the4,5-dichloro-imidazole-1-carboxylic acid aryl esters according to theinvention: 4,5-dichloro-2-trifluoromethylimidazole-1-carboxylic acidphenyl ester, 4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid2-methylphenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid4-methylphenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid2-chlorophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid4-chlorophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid2,4-dichlorophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid2-methyl-4-chlorophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid 4-bromophenylester, 4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid4-fluorophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid3-trifluoromethylphenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid 4-nitrophenylester, 4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid4-cyanophenyl ester,4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid4-carbethoxyphenyl ester, 4,5-dichloro-2-cyano-imidazole-1-carboxylicacid phenyl ester, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid methyl ester, 4,5-dichloro-imidazole-1-carboxylic acidphenyl ester 2-carboxylic acid isopropyl ester,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidhexyl ester, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid 2-methoxyethyl ester,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acid2-methyl-but-3-in-2-yl ester, 4,5-dichloro-imidazole-1-carboxylic acidphenyl ester 2-carboxylic acid ethylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidisopropylamide, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid tert.-butylamide, 4,5-dichloro-imidazole-1-carboxylicacid phenyl ester 2-carboxylic acid allylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acid2-methyl-but-3-inyl-2-amide, 4,5-dichloro-imidazole-1-carboxylic acidphenyl ester 2-carboxylic acid 3-methoxy-propylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidbenzylamide, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid 3,4-dichlorobenzylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidcyclopentylamide, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid cyclohexylamide, 4,5-dichloro-imidazole-1-carboxylicacid phenyl ester 2-carboxylic acid anilide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acid3,4-dichloroanilide, 4,5-dichloro-imidazole-1-carboxylic acid phenylester 2-carboxylic acid furyl-2-methylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic aciddiethylamide, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid N-formyl-ethylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidN-formyl-isopropylamide, 4,5-dichloro-imidazole-1-carboxylic acid phenylester 2-carboxylic acid N-formyl-tert.-butylamide,4,5-dichloro-imidazole-1-carboxylic acid phenyl ester 2-carboxylic acidpyrrolidide, 4,5-dichloro-imidazole-1-carboxylic acid phenyl ester2-carboxylic acid piperidide and 4,5-dichloro-imidazole-1-carboxylicacid phenyl ester 2-carboxylic acid morpholide.

As already mentioned, the compounds according to the invention can beused as plant protection agents. Above all, they are suitable for use asherbicides. In addition, they can also be employed as plant growthregulators and for combating insects and acarids, especially mites.

The active compounds according to the invention influence plant growthand can therefore be used as defoliants, desiccants, agents fordestroying broad-leaved plants and grasses germination inhibitors and,above all, weedkillers. Whether the compounds according to the inventionact as total herbicide or selective herbicides depends essentially onthe amount used.

By "weeds" in the broadest sense there are meant plants growing inlocations where they are not desired.

The active compounds according to the present invention may be used, forexample, to combat the following plants:

dicotyledon weeds such as mustard (Sinapis), cress (Lepidium), bed straw(Galium), chickweed (Stellaria), camomile (Matricaria), mayweed(Anthemis), gallant soldier (Galinsoga), goosefoot (Chenopodium), annulanettle (Urtica), groundsel (Senecio), pigweed (Amaranthus), purslane(Portulaca), cocklebur (Xanthium), bindweed (Convolvulus), morning glory(Ipomoea), knotweed (Polygonum), sesbania (Sesbania), ragweed(Ambrosia), spear thistle (Cirsium), common thistle (Carduus), sowthistle (Sonchus), field cress (Rorippa), toothcup (Rotala), falsepimpernel (Linderna), deadnettle (Lamium), speedwell (Veronica), mallow(Abutilon), emex (Emex), thornapple (Datura), violet (Viola),hemp-nettle (Galeopsis), poppy (Papaver) and knapweed (Centaurea); and

monocotyledon weeds such as barnyard grass (Echinochloa), foxtail(Setaria), wild millet (Panicum), crabgrass (Digitaria), timothy(Phleum), bluegrass (Poa), fescue (Festuca), goosegrass (Eleusine),signalgrass (Brachiaria), ryegrass (Lolium), cheat (Bromus), oats(Avena), flatsedge (Cyperus), sorghum (Sorghum), quackgrass (Agropyron),Bermuda grass (Cynodon), Monocharia, fimbristylis (Fimbristylis),arrowhead (Sagittaria), spikerush (Eleocharis), bulrush (Scirpus),paspalum (Paspalum), Ischaemum, gooseweed (Sphenoclea), crowfoot grass(Dactyloctenium), redtop (Agrostis), meadow foxtail (Alopecurus) andsilky bent-grass (Apera).

The active compounds according to the present invention may be used, forexample, as selective herbicides in the following cultures:

dicotyledon cultures such as cotton (Gossypium), soya bean (Glycine),beet (Beta), carrot (Daucus), bean (Phaseolus), pea (Pisum), potato(Solanum), flax (Linum), sweet potato (Ipomoea), broad bean (Vicia),tobacco (Nicotiana), tomato (Lycopersicon), groundnut (Arachis), cabbage(Brassica), lettuce (Lactuca), cucumber (Cucumis) and marrow(Cucurbita); and

monocotyledon cultures such as rice (Oryza), maize (Zea), wheat(Triticum), barley (Hordeum), oats (Avena), rye (Secale), sorghum(Sorghum), millet (Panicum), sugar cane (Saccharum), pineapple (Ananas),asparagus (Asparagus) and onion (Allium).

However, the use of the active compounds according to the invention isin no way restricted to these plants or even to the indicated genera butalso embraces other plants, in the same way.

Depending on the concentration, the compounds can be used for the totalcombating of weeds, for example on industrial terrain and railway tracksand on paths and squares with and without trees. Equally, the compoundscan be employed for combating weeds in perennial cultures, for exampleforestry plantings, decorative tree plantings, orchards, vineyards,citrus groves, nut orchards, banana plantations, coffee plantations, teaplantations, rubber plantations, oil palm plantations, soft fruitplantings and hopfields, and for the selective combating of weeds inannual cultures.

The active compounds according to the instant invention can be utilized,if desired, in the form of the usual formulation or compositions withconventional inert (i.e. plant compatible) herbicide or plant growthregulant diluents or extenders, i.e. diluents, carriers or extenders ofthe type usable in conventional pesticide formulations or compositions,e.g. conventional pesticide dispersible carrier vehicles such as gases,solutions, emulsions, wettable powders, suspensions, powder dustingagents, foams, pastes, soluble powders, granules, aerosols,suspension-emulsion concentrates, seed-treatment powders, natural andsynthetic materials impregnated with active compound, very fine capsulesin polymeric substances and in coating compositions, for use on seed,and formulations used with burning equipment, such as fumigatingcartridges, fumigating cans, fumigating coils and the like, as well asULV cold mist and warm mist formulations.

These are prepared in known manner, for instance by extending the activecompounds with conventional herbicides or plant growth regulantsdispersible liquid diluent carriers and/or dispersible solid carriersoptionally with the use of carrier vehicle assistants, e.g.,conventional H or PGR surface-active agents, including emulsifyingagents and/or dispersing agents, whereby, for example, in the case wherewater is used as diluent, organic solvents may be added as auxiliarysolvents. The following may be chiefly considered for use asconventional carrier vehicles for this purpose: aerosol propellantswhich are gaseous at normal temperatures and pressures, such ashalogenated hydrocarbons (dichlorodifluoromethane ortrichlorofluoromethane) as well as butane, propane, nitrogen and carbondioxide; inert dispersible liquid diluent carriers, including inertorganic solvents, such as aromatic hydrocarbons (e.g. benzene, toluene,xylene, alkyl naphthalenes, etc), halogenated, especially chlorinated,aromatic hydrocarbons (e.g. chlorobenzenes, etc.), cycloalkanes, (e.g.cyclohexane, etc.), paraffins (e.g. petroleum or mineral oil fractions),chlorinated aliphatic hydrocarbons (e.g. methylene chloride,chloroethylenes, etc.), alcohols (e.g. methanol, ethanol, propanol,butanol, glycol, etc.), as well as ethers and esters thereof (e.g.glycol monomethyl ether, etc.), amines (e.g. ethanolamine, etc.), amides(e.g. dimethyl formamide, etc.), sulfoxides (e.g. dimethyl sulfoxide,etc.), acetonitrile, ketones (e.g. acetone, methyl ethyl ketone, methylisobutyl ketone, cyclohexanone, etc.), and/or water; as solid carriers,ground natural minerals, such as kaolins, clays, talc, chalk, quartz,attapulgite, montmorillonite or diatomaceous earth, and ground syntheticminerals, such as highly-dispersed silicic acid, alumina and silicates;as solid carriers for granules; crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, maize cobs and tobaccostalks; whereas the following may be chiefly considered for use asconventional carrier assistants, e.g. surface-active agents, for thispurpose: emulsifying agents, such as non-ionic and/or anionicemulsifying agents (e.g. polyethylene oxide esters of fatty acids,polyethylene oxide ethers of fatty alcohols, alkyl sulfates, alkylsulfonates, aryl sulfonates, albumin hydrolyzates, etc., and especiallyalkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc.);and/or dispersing agents, such as lignin, sulfite waste liquors, methylcellulose, etc.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulations.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

Such active compounds may be employed alone or in the form of mixtureswith one another and/or with such solid and/or liquid dispersiblecarrier vehicles and/or with other known compatible active agents,especially other plant protection agents, such as other insecticides,acaricides, fungicides, bactericides, rodenticides and fertilizers, ifdesired, or in the form of particular dosage preparations for specificapplication made therefrom, such as solutions, emulsions, suspensions,powders, pastes, and granules which are thus ready for use.

As concerns commercially marketed preparations, these generallycontemplate carrier composition mixtures in which the active compound ispresent in an amount substantially between about 0.1-95% by weight, andpreferably 0.5-90% by weight, of the mixture, whereas carriercomposition mixtures suitable for direct application or fieldapplication generally contemplate those in which the active compound ispresent in an amount substantially between 0.0000001-100, preferably0.01-10%, by weight of the mixtures. Thus, the present inventioncontemplates overall compositions which comprise mixtures of aconventional dispersible carrier such as (1) a dispersible inert finelydivided carrier solid, and/or (2) a dispersible carrier liquid such asan inert organic solvent and/or water, preferably including asurface-active effective amount of a carrier vehicle assistant, e.g. asurface-active agent, such as an emulsifying agent and/or a dispersingagent, and an amount of the active compound which is effective for thepurpose in question and which is generally between about 0.0001-95%, andpreferably 0.01-95%, by weight of the mixture.

The amount of active compound used can vary within a fairly wide range.It depends essentially on the nature of the desired effect. In general,the amounts used are from 0.1 to 20 kg of active compound per hectare,preferably from 0.2 to 15 kg/ha.

The compounds according to the invention are especially suitable for theselective combating of weeds in crops of cultured plants such ascereals, cotton and maize.

They may be used both in accordance with the pre-emergence process andin accordance with the post-emergence process.

The present invention also provides a herbicidal,plant-growth-regulating, insecticidal or acaricidal compositioncontaining as active ingredient a compound of the present invention inadmixture with a solid or liquified gaseous diluent or carrier or inadmixture with a liquid diluent or carrier containing a surface-activeagent.

The present invention also provides a method of combating weeds, insectsor acrids which comprises applying to the weeds, insects or acaride, orto a habitat thereof, a compound of the present invention alone or inthe form of a composition containing as active ingredient a compound ofthe present invention in admixture with a diluent or carrier.

The present invention also provides a method of regulating the growth ofplants which comprises applying to the plants, or to a habitat thereof,a compound of the present invention alone or in the form of acomposition containing as active ingredient a compound of the presentinvention in admixture with a diluent or carrier.

The present invention further provides crops protected from damage byweeds, insects or acarids by being grown in areas in which immediatelyprior to and/or during the time of the growing a compound of the presentinvention was applied alone or in admixture with a diluent or carrier.

The present invention further provides plants, the growth of which hasbeen regulated by their being grown in areas in which immediately priorto and/or during the time of the growing a compound of the presentinvention was applied alone or in admixture with a diluent or carrier.

It will be seen that the usual methods of providing a harvested crop maybe improved by the present invention.

The herbicidal activity of the compounds of this invention isillustrated by the following biotest Examples.

In these Examples, the compounds according to the present invention areeach identified by the number (given in brackets) of the correspondingpreparative Example, which will be found later in this specification.

The known comparison compounds are identified as follows: ##STR24##

EXAMPLE A

Pre-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound was mixed with the stated amount of solvent, thestated amount of emulsifier was added and the concentrate was dilutedwith water to the desired concentration.

Seeds of the test plants were sown in normal soil and, after 24 hours,watered with the preparation of the active compound. It was expedient tokeep constant the amount of water per unit area. The concentration ofthe active compound in the preparation was of no importance, only theamount of active compound applied per unit area being decisive. Afterthree weeks, the degree of damage to the plants was determined in %damage in comparison to the development of the untreated control. Thefigures denoted:

0%=no action (like untreated control)

100%=total destruction

The active compounds, the amounts applied and the results can be seenfrom the table which follows:

                                      Table A                                     __________________________________________________________________________             Amount of                                                                     active com-                                                                   pound used,                                                                          Echino-                                                                            Cheno-                                                                             Gallin-                                                                            Stella-   Matri-                                                                             Sina-                           Active compound                                                                        kg/ha  chloa                                                                              podium                                                                             soga ria  Lolium                                                                             caria                                                                              pis Maize                                                                             Oats                                                                              Cotton              __________________________________________________________________________    (1)      5      100  100  100  100  100  100  100 100 100 100                 (2)      5      100  100  100  100  100  100  100 40  100 100                 (16)     5      100  100  100  100   80   90  100  0   10 0                   (4)      5      100  100  100  100  100  100  100  0   0  0                   (15)     5      100  100  100  100  100  100  100 80   90 100                 (A)      5       60   0    0    20   0    80   0   0   0  0                   __________________________________________________________________________

EXAMPLE B

Post-emergence Test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound 1 part by weight ofactive compound was mixed with the stated amount of solvent, the statedamount of emulsifier was added and the concentrate was then diluted withwater to the desired concentration.

Test plants which had a height of 5-15 cm were sprayed with thepreparation of the active compound in such a way as to apply the amountsof active compound per unit area which are indicated in the table. Theconcentration of the spray liquor was so chosen that the amounts ofactive compound shown in the table were applied to 2,000 l of water/ha.After three weeks, the degree of damage to the plants was rated in %damage in comparison to the development of the untreated control. Thefigures denoted:

0%=no action (like untreated control)

100%=total destruction.

The active compounds, the amounts applied and the results can be seenfrom the table which follows:

                                      Table B                                     __________________________________________________________________________         Amount of                                                                     active com-                                                              Active                                                                             pound used,                                                                          Echino-                                                                            Cheno-                                                                             Gallin-                                                                            Stella-   Matri-    Sina-                          compound                                                                           kg/ha  chloa                                                                              podium                                                                             soga ria  Urtica                                                                             caria                                                                              Daucus                                                                             pis Oats                                                                             Cotton                                                                             Wheat              __________________________________________________________________________    (1)  1      100  100  100  100  100  100  100  100 100                                                                               0   100                (2)  1      100  100  100  100  100  100  100  100  30                                                                              10    20                (16) 1      100  100  100  100  100  100  100  100 100                                                                              100  100                (4)  1      100  100  100  100  100  100  100  100 100                                                                              100  100                (15) 1      100  100  100  100  100  100  100  100  40                                                                              60    40                (A)  1       60   40   20   80   40   20   0    60  60                                                                              40    60                __________________________________________________________________________

The process of this invention is illustrated by the followingpreparative Examples.

EXAMPLE 1 ##STR25##

20.5 g (0.1 mol) of 4,5-dichloro-2-trifluoromethyl-imidazole weredissolved in 150 ml of dioxane. 10.1 g (0.1 mol) of triethylamine wereadded thereto and 16.05 g (0.1 mol) of chloroformic acid phenyl esterwere then added dropwise whilst cooling at 10°-15° C. The mixture wasstirred for a further 2 hours at room temperature, the triethylaminehydrochloride which had separated out was filtered off and the filtratewas evaporated in vacuo. The oily residue was distilled. The mainfraction boiled at 106.5°-107° C./0.08 mm Hg. 28.6 g (88% of theory) of4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acid phenyl esterwere obtained.

EXAMPLE 2 ##STR26##

Variant a

16.2 g (0.1 mol) of 4,5-dichloro-2-cyano-imidazole were dissolved in 150ml of dioxane. 10.1 g (0.1 mol) of triethylamine were added thereto and16.05 g (0.1 mol) of chloroformic acid phenyl ester were added dropwisewhilst cooling at 10°-15° C. The mixture was stirred for a further 2hours at room temperature, the triethylamine hydrochloride which hadseparated out was filtered off and the filtrate was evaporated in vacuo.The residue was stirred with water, filtered off, rinsed with water anddried. 25 g (89% of theory) of4,5-dichloro-2-cyano-imidazole-1-carboxylic acid phenyl ester, having amelting point of 156°-158° C. after recrystallisation from wash benzine,were obtained.

Variant b

18.4 g (0.1 mol) of the sodium salt of 4,5-dichloro-2-cyano-imidazole(prepared from 4,5-dichloro-2-cyano-imidazole and the equimolar amountof sodium ethylate in ethanol, followed by evaporation to dryness) weresuspended in 150 ml of toluene. 16.05 g (0.1 mol) of chloroformic acidphenyl ester were added dropwise thereto, whilst stirring at 15°-20° C.The mixture was further stirred for 1 hour at room temperature and 1hour at 40°-50° C. The insoluble constituents were filtered off and thefiltrate was evaporated in vacuo. 23 g (82% of theory) of4,5-dichloro-2-cyano-imidazole-1-carboxylic acid phenyl ester remain asthe residue, which after recrystallisation from wash benzine had amelting point of 156°-158° C.

Variant c

16.2 g (0.1 mol) of 4,5-dichloro-2-cyano-imidazole and 16.05 g (0.1 mol)of chloroformic acid phenyl ester were dissolved in 150 ml ofacetonitrile. 13.8 g (0.1 mol) of potassium carbonate were introduced inportions at room temperature, whilst stirring. The mixture was stirredfor a further hour at room temperature and was then gradually heated tothe boil, and boiled under reflux until the evolution of CO₂ had ended.The salts were then filtered off and the filtrate was evaporated invacuo. The residue was treated with water, filtered off, rinsed withwater and dried. 20.6 g (73% of theory) of4,5-dichloro-2-cyano-imidazole-1-carboxylic acid phenyl ester, having amelting point of 156°-158° C. after recrystallisation from wash benzine,were obtained.

The following compounds were obtained by procedures analogous to thosedescribed above.

                                      Table 1                                     __________________________________________________________________________     ##STR27##                                                                                                          Melting point (°C.)                                                                    Recrystallised          Example No.                                                                           X               Aryl          Boiling point (°C./mm                                                                  from                    __________________________________________________________________________             ##STR28##                                                                                     ##STR29##    78-80           wash benzine                                                                  (gasoline)              4                                                                                      ##STR30##                                                                                     ##STR31##    155-159/0.08                            5                                                                                      ##STR32##                                                                                     ##STR33##    66-68           wash benzine            6                                                                                      ##STR34##                                                                                     ##STR35##    165-170/0.098                           7                                                                                      ##STR36##                                                                                     ##STR37##    72-73           wash benzine            8                                                                                      ##STR38##                                                                                     ##STR39##    92-93           wash benzine            9                                                                                      ##STR40##                                                                                     ##STR41##    90-92           wash benzine            10                                                                                     ##STR42##                                                                                     ##STR43##    136-137         toluene                 11                                                                                     ##STR44##                                                                                     ##STR45##    106-108         wash benzine            12      CN                                                                                             ##STR46##    169-170         wash benzine            13      CN                                                                                             ##STR47##    175-176         wash benzine            14                                                                                     ##STR48##                                                                                     ##STR49##    96-98           wash benzine            15                                                                                     ##STR50##                                                                                     ##STR51##    104-106         wash benzine            16                                                                                     ##STR52##                                                                                     ##STR53##    98-100          wash benzine            17                                                                                     ##STR54##                                                                                     ##STR55##    180-190/0.09                            18                                                                                     ##STR56##                                                                                     ##STR57##    130-132         wash                    __________________________________________________________________________                                                          benzine             

PREPARATION OF THE STARTING MATERIALS EXAMPLE 19 ##STR58##

380 g (2 mol) of 4,5-dichloro-2-trichloromethyl-imidazole prepared bytreating 4,5-dichloro-2-dichloromethylene-imidazole with dry HCl at -20°to +600° C., were initially introduced into a fluorination autoclave and400 ml of hydrogen fluoride were added at 0° C. The autoclave was closedand a blanketing pressure of 2 atmospheres of chlorine was applied. Themixture was heated up to 100° C. in the course of 2 hours and then up to140° C. in the course of a further 2 hours and this temperature wasmaintained for a further three and a half hours. The pressure, whichrose due to the hydrogen chloride formed, was let down by means of acondenser with the aid of a control valve set at 20 bars. After thereaction had ended, the mixture was allowed to cool, the pressure waslet down and excess hydrogen fluoride was distilled off. The residue wasdissolved in tetrahydrofuran; sodium fluoride was added to this solutionand the mixture was shaken and filtered. After stripping off thesolvent, 262 g (85.5% of theory) of4,5-dichloro-2-trifluoromethyl-imidazole were obtained in the form of acrystalline product with a melting point of 186°-188° C.

EXAMPLE 20 ##STR59##

25.4 g (0.1 mol) of 4,5-dichloro-2-trichloromethyl-imidazole prepared bytreating 4,5-dichloro-2-dichloromethylene-imidazole with dry HCl at -20°to +600° C., were introduced in small portions into 200 ml of ethanolsaturated with ammonia, whilst cooling with ice and stirring vigorously.The mixture was stirred for a further 30 minutes at 50° C., theconstituents which had not dissolved were then filtered off and thefiltrate was evaporated under reduced pressure. The combined residueswere dissolved in hot water. On acidifying the solution with dilutehydrochloric acid, the reaction product precipited out. This wasfiltered off, washed with water and dried. In this way 14.6 g (90% oftheory) of 4,5-dichloro-2-cyano-imidazole were obtained and afterrecrystallisation from toluene this had a melting point of 187°-189° C.

EXAMPLE 21 ##STR60##

560 g (2.56 mol) of 4,5-dichloro-2-dichloromethylene-imidazole wereadded to 1 kg (13.2 mol) of glycol monomethyl ether, whilst coolingslightly and stirring, at such a rate that the temperature of theexothermic reaction was maintained at 80°-100° C. Thereafter thereaction mixture was evaporated to dryness in vacuo. This gave4,5-dichloro-imidazole-2-carboxylic acid methoxy-ethyl ester invirtually quantitative yield. Melting point 130° C.

The same compound was obtained if4,5-dichloro-2-trichloromethylimidazole was employed in place of4,5-dichloro-2-dichloromethyleneimidazole. The reaction was carried outin the manner described above. However, it was appropriate to heat thereaction mixture to 90°-100° C. for a while after the addition of the4,5-dichloro-2-trichloromethyl-imidazole was complete.

The compounds of the formula ##STR61## listed in Table 2 below wereobtained analogously:

                  Table 2                                                         ______________________________________                                        Example                    Melting point                                      No.         R.sup.1        (° C.)                                      ______________________________________                                        22          CH.sub.3       160                                                23          CH(CH.sub.3).sub.2                                                                           168                                                24          CH.sub.2 --CH.sub.2 --Cl                                                                     136                                                25          CH.sub.2 --CH═CH.sub.2                                                                   105                                                ______________________________________                                    

EXAMPLE 26 ##STR62##

15.5 g (0.2 mol) of dimethylamine hydrochloride were added to a solutionof 21.8 g (0.1 mol) of 4,5-dichloro-2-dichloromethylene-imidazole in 100ml of dioxan and the mixture was heated for 2 hours to the refluxtemperature, whilst stirring. It was then allowed to cool and water wasadded. The product which hereupon precipitated was filtered off, washedwith water and dried. 14.3 g (68.5% of theory) of4,5-dichloro-imidazole-2-carboxylic acid dimethylamide, having a meltingpoint of 245° C. after recrystallisation from chlorobenzene, were thusobtained.

EXAMPLE 27 ##STR63##

Using the method described in Example 26, reaction of4,5-dichloro-2-dichloromethylene-imidazole with morpholine hydrochloridegave 4,5-dichloro-imidazole-2-carboxylic acid morpholide as acrystalline product, which after recrystallisation from acetonitrile hada melting point of 215° C.

EXAMPLE 28 ##STR64##

Variant (a)

654 g (3 mol) of 4,5-dichloro-2-dichloromethylene-imidazole in a finelypowdered form were added, in portions, in the course of about one hourto a mixture, which had been initially introduced, of 783 g (9 mol) ofisopropylformamide, 162 g (9 mol) of water and 3 liter of acetonitrile,at 0° C., whilst stirring and whilst cooling. The clear solution wasthen poured into 15 kg of ice water. The resulting white precipitate wasfiltered off, washed with water and dried. This gave 630 g (84% oftheory) of 4,5-dichloro-imidazole-2-carboxylic acidN-formyl-isopropylamide with a melting point of 142° C. The same resultwas also obtained without the addition of water.

Variant (b)

21.8 g (0.1 mol) of 4,5-dichloro-2-dichloromethylene-imidazole in afinely powdered form were added in portions to 87 g (1 mol) ofisopropyl-formamide, whilst stirring, and the reaction mixture warmed upto 40°-50° C. After the exothermic reaction had subsided, the reactionmixture was poured into excess ice water. A viscous precipitate firstformed and this solidified after standing for about one hour. After theproduct had been filtered off, washed with water and dried, 23 g of asubstance were obtained, the major part of which was identical with theproduct described under (a). Melting range about 132°-137° C. Byfractional crystallisation from acetonitrile, it was possible, afterseparating off a more sparingly soluble secondary component, to isolatethe product described under (a) in a pure form with a melting point of142° C.

EXAMPLE 29 ##STR65##

Variant (a)

From 4,5-dishloro-imidazole-2-carboxylic acid N-formylisopropylamide(see Example 28):

25 g (0.1 mol) of 4,5-dichloro-imidazole-2-carboxylic acidN-formyl-isopropylamide were stirred with 200 ml of concentratedsulphuric acid for about 15 minutes at 50°-70° C. After cooling, thereaction mixture was poured onto ice. The solid thus obtained wasfiltered off, washed with water until neutral and dried. This gave 16 g(72% of theory) of 4,5-dichloro-imidazole-2-carboxylic acidispropylamide with a melting point of 150° C.

Variant (b)

From 4,5-dichloro-2-dichloromethylene-imidazole ("one-vessel process"):

654 g (3 mol) of 4,5-dichloro-2-dishloromethylene-imidazole in a finelypowdered form were added in portions in the course of about one hour toa mixture, which had been initially introduced, of 783 g (9 mol) ofisopropylformamide and 162 g (9 mol) of water, whilst stirring and withgentle cooling, and the internal temperature rose to about 75° C.Subsequently, the mixture was heated to about 90°-110° C. for a furtherhalf hour. After cooling, the product was precipitated in water,filtered off, washed with water and dried. This gave 566 g (85% oftheory) of 4,5-dichloroimidazole-2-carboxylic acid isopropylamide with amelting point of 150° C.

EXAMPLE 30 ##STR66##

Using the method described in Example 29b, the reaction oftert.-butylformamide and 4,5-dichloro-2-dichloromethylene-imidazole gave4,5-dichloro-imidazole-2-carboxylic acid tert.-butylamide as acrystalline product of melting point 218° C.

EXAMPLE 31 ##STR67##

21.8 g (0.1 mol) of finely powdered4,5-dichloro-2-dichloromethylene-imidazole were added, whilst stirring,to a mixture of 12 g (0.125 mol) of aniline, 100 ml of water and 15 g(approx. 0.15 mol) of 37% strength aqueous hydrochloric acid at roomtemperature and the batch was then heated for about 1 hour to about 100°C. After cooling, the product which had precipitated was filtered off,washed with water and dried. 20.0 g (78% of theory) of4,5-dichloro-imidazole-2-carboxylic acid anilide, having a melting pointof 243° C. after recrystallisation from acetonitrile, were thusobtained.

EXAMPLE 32 ##STR68##

Dry hydrogen chloride was passed into a solution of 218 g (1.0 mol) of4,5-dichloro-2-dichloromethylene-imidazole in about 2 liters of drytoluene until the formation of a precipitate had ended (at least 1 mol).After cooling (the addition of HCl was exothermic), filtering off anddrying, 235 g (89% of theory) of 4,5-dichloro-2-trichloromethylimidazoleof melting point 210° C. (with decomposition) were obtained.

EXAMPLE 33 ##STR69##

40 g (0.55 mol) of dimethylformamide were added dropwise in the courseof about 10 minutes to a boiling solution of 100 g (0.46 mol) of4,5-dichloro-2-dichloromethyleneimidazole in 1 liter of petroleum ether(boiling range about 60° C.) and a precipitate separated out. Aftercooling, the petroleum ether was decanted off and the precipitate wasstirred with acetone. Subsequently it was filtered off and washed withacetone until the acetone which ran off was pale yellow. This gave 41 g(55% theory) of the dimeric ketene of the above formula in the form of apale yellow powder with a melting point of above 290° C.

What is claimed is:
 1. A 4,5-dichloro-imidazole-1-carboxylic acid arylester of the formula ##STR70## in which X represents a group ##STR71##in which R¹ represents a straight or branched alkyl radical with 1 to 6carbon atoms or straight or branched alkenyl or alkynyl, each with up to6 carbon atoms, which radicals can be carrying one or more substituentsselected from fluorine, chlorine, bromine, alkoxy with 1 to 6 carbonatoms and alkylmercapto with 1 to 6 carbon atoms,R² represents hydrogen,alkyl with 1 to 8 carbon atoms, alkenyl with up to 8 carbon atoms in theformyl group, R³ represents alkyl with 1 to 8 carbon atoms or alkenyl oralkynyl, each with up to 8 carbon atoms, it being possible for each ofthese alkyl, alkenyl and alkynyl radicals to carry one or moresubstituents selected from alkoxy with 1 to 4 carbon atoms andalkylmercapto with 1 to 4 carbon atoms, or R² and R³ conjointly with theadjoining nitrogen atom form a heterocyclic radical selected frompyrrolidinyl, piperidinyl and hexamethyleneimidinyl Y representshalogen, alkyl with 1 to 6 carbon atoms, trifluoromethyl, alkoxy with 1to 6 carbon atoms, alkylmercapto with 1 to 6 carbon atoms, nitro, cyanoor a ##STR72## group, in whichR⁴ represents alkyl with 1 to 6 carbonatoms and n represents 0, 1, 2, 3, 4, or
 5. 2. A compound according toclaim 1 wherein X represents a group --CO--OR¹ or --CO--NR² R³ inwhichR¹ represents a straight or branched alkyl radical with 1 to 6carbon atoms, which alkyl radical can carry one or more substituentsselected from fluorine, chlorine, bromine, alkoxy with 1 to 4 carbonatoms and alkylmercapto with 1 to 4 carbon atoms or R¹ represents astraight chain or branched alkenyl or alkynyl radical, each with up to 6carbon atoms; R² represents hydrogen, straight or branch chained alkylwith 1 to 6 carbon atoms, straight or branched alkenyl with up to 6carbon atoms or the formyl group; R³ represents straight or branchedalkyl with 1 to 6 carbon atoms or straight or branched alkenyl oralkynyl each with up to 6 carbon atoms, optionally substituted by one ormore substituents selected from the group consisting of alkoxy with 1 to3 carbon atoms and alkylmercapto with 1 to 3 carbon atoms; or R² and R³conjointly with the adjoining nitrogen atom form a heterocyclic ringselected from pyrrolidinyl, piperidinyl and hexamethyleneimidinyl; and Yrepresents fluorine, chlorine, bromine, alkyl with 1 to 4 carbon atoms,alkoxy with 1 to 4 carbon atoms, alkylmercapto with 1 to 4 carbon atoms,trifluoromethyl, nitro, cyano or a --CO--OR⁴ group, in which R⁴represents alkyl with 1 to 4 carbon atoms; and n represents 0, 1, 2, or3.
 3. A compound according to claim 1 having the following formula##STR73##
 4. A compound according to claim 1 having the followingformula ##STR74##
 5. A compound according to claim 1 having thefollowing formula ##STR75##
 6. A compound according to claim 1 havingthe following formula ##STR76##
 7. A compound according to claim 1having the following formula ##STR77##
 8. A compound according to claim1 having the following formula ##STR78##
 9. A compound according toclaim 1 having the following formula ##STR79##
 10. A compound accordingto claim 1 having the following formula ##STR80##
 11. A compoundaccording to claim 1 having the following formula ##STR81##
 12. Acompound according to claim 1 having the following formula ##STR82## 13.A compound according to claim 1 having the following formula ##STR83##14. A herbicide containing as an active ingredient a herbicidallyeffective amount of a compound according to claim 1 in admixture with adiluent.
 15. A method of protecting a plant which comprises applying tothe plant or its habitat a herbicidally effective amount of a compoundaccording to claim
 1. 16. A method according to claim 15 wherein saidcompound is 4,5-dichloro-2-trifluoromethyl-imidazole-1-carboxylic acidphenyl ester, 4,5-dichloro-2-cyano-imidazole-1-carboxylic acid phenylester, a compound of the formula ##STR84## a compound of the formula##STR85## or a compound of the formula ##STR86##
 17. A method accordingto claim 15 wherein said 4,5-dichloro-imidazole-1-carboxylic acid arylester is applied to a plant or its habitat prior to emergence of anyweeds.
 18. A method according to claim 15 wherein said4,5-dichloro-imidazole-1-carboxylic acid aryl ester is applied to aplant which is selected from the group consisting of oats, cotton, wheatand maize.
 19. A compound according to claim 1 having the followingformula ##STR87##
 20. A compound according to claim 1 having thefollowing formula ##STR88##
 21. An insecticide containing as an activeingredient an insecticidally effective amount of a compound according toclaim 1 in admixture with a diluent.
 22. An acaricide containing as anactive ingredient an acaricidally effective amount of a compoundaccording to claim 1 in admixture with a diluent.
 23. A plant growthregulant containing as an active ingredient a plant growth regulatinglyeffective amount of a compound according to claim 1 in admixture with adiluent.
 24. A method of protecting a plant which comprises applying tothe plant or its habitat an insecticidally effective amount of acompound according to claim
 1. 25. A method of protecting a plant whichcomprises applying to the plant or its habitat an acaricidally effectiveamount of a compound according to claim
 1. 26. A method of regulatingthe growth of a plant which comprises applying to the plant or itshabitat a plant growth regulatingly effective amount of a compoundaccording to claim 1.